Ab initio study of the structure of the alpha-MoO3 solid and study of the adsorption of H2O and CO molecules on its (100) surface
Ab initio study of the structure of the alpha-MoO3 solid and study of the adsorption of H2O and CO molecules on its (100) surface
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DOI：
10.1021/jp953727w
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发表时间：
1996-06-20
影响因子：
--
通讯作者：
Sautet, P
中科院分区：
文献类型：
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作者：
Papakondylis, A;Sautet, P
采用从头算周期性Hartree-Fock计算并对相关效应进行了修正，研究了α - moo3的晶体结构。研究了固体内部键合的性质和能量学，并将其与晶体的几何形状联系起来。由共享O角的MoO4四面体形成的（MoO3）(x)链是固体的基本结构单元。简单的Mo…这些链之间的静电相互作用导致MoO3形成自然层，并在Mo原子周围建立6倍配位。α - moo3固体的（100）表面含有五配位Mo原子，这是由于链间相互作用的断裂而产生的，具有路易斯酸性质。发现H2O和CO分子在这些Mo位点上的吸附本质上是静电性质的，恢复了Mo原子周围的块状环境。
Ab initio periodic Hartree-Fock calculations along with corrections for correlation effects have been carried out to study the crystal structure of alpha-MoO3. The nature and energetics of bonding within the solid have been investigated and related to the geometry of the crystal. (MoO3)(x) chains formed by MoO4 tetrahedra sharing common O corners were shown to be the basic structural units of the solid. Simple Mo ... O electrostatic interactions between these chains lead to the formation of the natural layers of MoO3 and establish a 6-fold coordination around Mo atoms. The (100) surface of alpha-MoO3 solid contains pentacoordinated Mo atoms, brought about by the breaking of interchain interactions, and possessing a Lewis acid character. The adsorption of H2O and CO molecules on these Mo sites was found to be of, essentially, electrostatic nature restoring a bulklike environment around Mo atoms.